针对片上网络(network on chip,简称NoC)的节点数量少、距离近、物理实现复杂度受到限制的特点,提出了一种新的Xmesh拓扑结构,并为该结构提出了XM路由算法.该结构在经典的mesh结构的基础上添加了两个对角线型的回边,缩短了节点间的距离...针对片上网络(network on chip,简称NoC)的节点数量少、距离近、物理实现复杂度受到限制的特点,提出了一种新的Xmesh拓扑结构,并为该结构提出了XM路由算法.该结构在经典的mesh结构的基础上添加了两个对角线型的回边,缩短了节点间的距离,而且路由计算的复杂性不高,实现的复杂度基本没有增加.将Xmesh与经典的Mesh和Torus结构进行了理论分析比较,同时,在Popnet模拟器上基于均衡负载和热点负载两种负载模式进行性能比较.模拟结果表明,Xmesh平均延时不到Mesh结构的70%.对于均衡负载,当网络规模较小时,Xmesh的延时比Torus的更小;对于热点负载,当热点距离网络中心或者对角线比较近时,Xmesh的延时比Torus的小10%～30%.反之,其延时比Torus的大10%～30%.总的来说,Xmesh的性能与Torus比较接近,但其物理实现更为简单,Xmesh比Mesh结构的性能更好.展开更多
介绍了静态频率变换器(static frequency converter,SFC)在大型燃气轮机组启动中的作用。对SFC的主要工作方式——脉冲模式换流和负载换向模式换流进行了深入具体分析,从而得出两种换流模式下SFC的工作原理。在实际应用中,提出应注意励...介绍了静态频率变换器(static frequency converter,SFC)在大型燃气轮机组启动中的作用。对SFC的主要工作方式——脉冲模式换流和负载换向模式换流进行了深入具体分析,从而得出两种换流模式下SFC的工作原理。在实际应用中,提出应注意励磁系统与SFC的配合问题,在机组转速小于18%额定转速时,励磁调节器采用手动方式,在机组转速大于20%额定转速时,则采用自动方式。展开更多
In order to mitigate the effects of space adaptation syndrome(SAS) and improve the training efficiency of the astronauts, a novel astronaut rehabilitative training robot(ART) was proposed. ART can help the astronauts ...In order to mitigate the effects of space adaptation syndrome(SAS) and improve the training efficiency of the astronauts, a novel astronaut rehabilitative training robot(ART) was proposed. ART can help the astronauts to carry out the bench press training in the microgravity environment. Firstly, a dynamic model of cable driven unit(CDU) was established whose accuracy was verified through the model identification. Secondly, to improve the accuracy and the speed of the active loading, an active loading hybrid force controller was proposed on the basis of the dynamic model of the CDU. Finally, the actual effect of the hybrid force controller was tested by simulations and experiments. The results suggest that the hybrid force controller can significantly improve the precision and the dynamic performance of the active loading with the maximum phase lag of the active loading being 9° and the maximum amplitude error being 2% at the frequency range of 10 Hz. The controller can meet the design requirements.展开更多
基金Supported by the National Natural Foundation of China for Distinguished Young Scholars under Grant No.60325205(国家杰出青年基金)the National Natural Science Foundation of China under Grant No.60673146(国家自然科学基金)+6 种基金the National High-Tech Research and Development Plan of China under Grant Nos.2005AA1100102005AAl19020(国家高技术研究发展计划(863))the National Basic Research Program of China under Grant No.2005CB321600(国家重点基础研究发展计划(973))the Natural Science Foundation of Beijing of China under Grant No.4072024(北京市自然科学基金)Knowledge Innovation Program of the Institute of Computing Technologythe Chinese Academy of Sciences under Grant Nos.2005624020066012(中国科学院计算技术研究所知识创新课题)
文摘针对片上网络(network on chip,简称NoC)的节点数量少、距离近、物理实现复杂度受到限制的特点,提出了一种新的Xmesh拓扑结构,并为该结构提出了XM路由算法.该结构在经典的mesh结构的基础上添加了两个对角线型的回边,缩短了节点间的距离,而且路由计算的复杂性不高,实现的复杂度基本没有增加.将Xmesh与经典的Mesh和Torus结构进行了理论分析比较,同时,在Popnet模拟器上基于均衡负载和热点负载两种负载模式进行性能比较.模拟结果表明,Xmesh平均延时不到Mesh结构的70%.对于均衡负载,当网络规模较小时,Xmesh的延时比Torus的更小;对于热点负载,当热点距离网络中心或者对角线比较近时,Xmesh的延时比Torus的小10%～30%.反之,其延时比Torus的大10%～30%.总的来说,Xmesh的性能与Torus比较接近,但其物理实现更为简单,Xmesh比Mesh结构的性能更好.
文摘介绍了静态频率变换器(static frequency converter,SFC)在大型燃气轮机组启动中的作用。对SFC的主要工作方式——脉冲模式换流和负载换向模式换流进行了深入具体分析,从而得出两种换流模式下SFC的工作原理。在实际应用中,提出应注意励磁系统与SFC的配合问题,在机组转速小于18%额定转速时,励磁调节器采用手动方式,在机组转速大于20%额定转速时,则采用自动方式。
基金Project(61175128) supported by the National Natural Science Foundation of ChinaProject(2008AA040203) supported by the National High Technology Research and Development Program of ChinaProject(QC2010009) supported by the Natural Science Foundation of Heilongjiang Province,China
文摘In order to mitigate the effects of space adaptation syndrome(SAS) and improve the training efficiency of the astronauts, a novel astronaut rehabilitative training robot(ART) was proposed. ART can help the astronauts to carry out the bench press training in the microgravity environment. Firstly, a dynamic model of cable driven unit(CDU) was established whose accuracy was verified through the model identification. Secondly, to improve the accuracy and the speed of the active loading, an active loading hybrid force controller was proposed on the basis of the dynamic model of the CDU. Finally, the actual effect of the hybrid force controller was tested by simulations and experiments. The results suggest that the hybrid force controller can significantly improve the precision and the dynamic performance of the active loading with the maximum phase lag of the active loading being 9° and the maximum amplitude error being 2% at the frequency range of 10 Hz. The controller can meet the design requirements.
